By Adrian Croft
BRUSSELS (Reuters) - NATO Secretary-General Jens Stoltenberg accused Russia on Monday of violating a ceasefire agreement in eastern Ukraine by sending large deliveries of advanced weapons to pro-Russian separatists.
Ukraine said on Sunday that a convoy of 106 vehicles had entered its eastern territory from Russia without Kiev's permission and accused Moscow of using humanitarian aid shipments to send weapons and ammunition to separatist rebels.
"We see a significant military buildup in and around Ukraine," Stoltenberg told a news conference. "Large transfers of Russian advanced weapons, equipment and military personnel to violent separatists."
Moscow denies using humanitarian convoys to transport weapons and rejects Western accusations that it is arming the rebels and sending fighters to aid them. It accuses the West and Kiev of pressing a campaign of indiscriminate violence in the eastern territories of Luhansk and Donetsk.
Commenting on the convoy, Stoltenberg said the best way to improve the humanitarian situation in eastern Ukraine was to stop violations of the Minsk agreement, intended to halt the conflict in eastern Ukraine, and to respect the ceasefire.
"We are seeing that the separatists and Russia (are) not doing that. Russia is fuelling the conflict by providing ... equipment and other kinds of support for the separatists and thereby undermining and violating the ceasefire and also the efforts to create a peaceful, negotiated solution," he said.
NATO foreign ministers meet in Brussels on Tuesday to discuss the situation in Ukraine and to review steps the 28-nation alliance has taken to boost its defences and to reassure nervous eastern European allies following Moscow's annexation of Ukraine's Crimea region in March.
They will agree to continue the measures, which include exercises and rotations of small numbers of troops to eastern Europe, throughout 2015.